Live-cell imaging and analysis of APOE4 and lipid biology in the pathogenesis of AD and TBI

FY21 DURIP Funds for:Possession of the 4 allele of apolipoprotein E (APOE) is the major genetic risk factor for lateonset Alzheim ers disease (AD) and also leads to worse outcomes after traumatic brain injury (TBI). In addition, there seems to be a synergistic effect between APOE4, TBI and AD, with APOE4 carriers who experience a TBI having a 10-fold risk of developing AD. While the reaso n for this association between APOE4, AD and TBI is not yet understood, it is interesting to note that both AD and TBI are marked by neurotoxic tau pathology, and APOE4 has recently been shown to increase the toxicity of tauopathy-afflicted neurons. In order t o understand this association between APOE4 expression and tauopathy-driven neurodegeneration in AD and TBI, my lab has developed an in vitro assay for measuring acute neurotoxicity of mutant tau-expressing neurons in an APOE expressing co-culture system. This system allows us to track the degenerationof tauopathy-afflicted neurons in a high-throughput, 96-well plate assay format. Using t his assay, we can monitor the effect of APOE4 genotype on tau pathology, investigate the mechanisms responsible for the related ne urotoxicity, and potentially identify novel drug candidates that can prevent this effect from occurring. Unfortunately, however, ou r capabilities for performing this assay are limited at the moment. Utilizing a fluorescent plate-reader, we can monitor overall n euronal death; however, this method lacks the sensitivity, resolution, and temporal capabilities to fully interrogate this phenomen on. Therefore, in order to further elucidate the role of APOE4expression in the neurotoxicity of tauopathy in both AD and TBI, and how to prevent it, we are requesting funds to purchase a Cytation 7 live-imaging system from Biotek. With this system, we will be able to perform live-cell imaging to track the kinetics of this neurotoxicity in different conditions, as well as to simultaneousl y monitor the activation states of the co-cultured astrocytes and microglia, and also to perform high-throughput assays to identify novel drug candidates that can prevent this neurotoxicity. We believe that this capability will allow us to make important contri butions towards improving the lives of APOE4-carrying military personnel and veterans